SUBROUTINE PLRLN

   PLRLN plots a solid curve through the set of coordinate points in polar form stored in r and t arrays. Symbols may be inserted at selected intervals. Angle values stored in the t array are in degrees referenced to horizontal. Coordinates are calculated as follows:

          r=(r-rmin)/dr
          xplotted=r*cos(t*pi/180)
          yplotted=r*sin(t*pi/180)

CALL PLRLN (r,t,n,j,l,ir,rmin,dr)

r     (R): array of radial values to be plotted
t     (R): array of angle values
n     (I): number of points to plot
j     (I): plotting symbol option flag
           > 0 : symbol plotted every jth point with connecting lines
           = 0 : line plotted only with no symbols
           < 0 : symbols plotted only, no connecting line
l     (I): symbol number (see SYMBOL)
ir    (I): start index in r and t arrays
rmin  (R): minimum radius scale factor
dr    (R): scale factor